Qualcomm Incorporated

Ngar Loong A Chan

Jonghoon Choi

Bindu Gupta

A frequency divider circuit having two stages of transistors has improved performance at low supply voltages. The circuit may include cross-coupled PMOS and NMOS transistors, in which the input signal to be frequency divided is supplied to the body of the PMOS and/or NMOS transistors. The input signal may be coupled to the PMOS and/or NMOS transistors through capacitive or inductive coupling. The input signal to the PMOS and/or NMOS transistors may be generated by a voltage controlled oscillator circuit. With the frequency divider circuit having inputs signals coupled to the body of the PMOS and/or NMOS transistors supply voltages as low as 0.5 Volts may be possible.

Compact high frequency divider

Techniques for providing a switchable inductor network having configurable inductance in response to a control signal. The switchable inductor network may adopt a fully symmetric architecture to reduce the effects of parasitic elements in differential mode operation. The switchable inductor network is particularly suitable for multi-mode communications circuitry applications, e.g., in the design of a voltage-controlled oscillator (VCO) or an amplifier or buffer in such circuitry.

Switchable inductor network

An integrated circuit for transmit and receive matching is described. The integrated circuit includes a transmit amplifier. The transmit amplifier includes a first transistor, a second transistor and a first inductor. The first inductor couples the first transistor to the second transistor. The integrated circuit also includes a low noise amplifier. The low noise amplifier includes a third transistor, a fourth transistor, the first inductor, a second inductor, a third inductor and a transformer. The second inductor couples the first inductor to the third transistor. The third inductor couples the third transistor to ground.

Area efficient concurrent matching transceiver

Methods and apparatus for a resonant transmit/receive switch with transformer gate/source coupling. The resonant transmit/receive (T/R) switch includes a switchable inductor having a first inductance value for use in receive (Rx) mode and a second inductance value for use in transmit (Tx) mode. The first inductance value is used for input matching to a low noise amplifier in Rx mode. The second inductance value is selected to resonant with parasitic capacitance of the antenna port to produce a high impedance in Tx mode. In one implementation, the switchable inductor is gate sourced coupled to at least one of first and second inductors of a low noise amplifier (LNA), thereby allowing use of smaller inductors due to the resulting coupling factor.

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Santa Clara, CA, United States of America

Ngar Loong A Chan